Does it also hang with ffmpeg?
One possibility to test is:
$ ffmpeg -i 20051210-w50s.flv -f null -

If you cannot reproduce the hang, please recompile with --enable-cross-compile --cross-prefix=arm-angstrom-linux-gnueabi --target-os=linux (or whatever is the necessary minimum to compile an optimized neon binary).

It doesn't hang with ffmpeg since ffmpeg may not decode frame. I found it hangs when the third packet of size of 1112 bytes enter the said function. When I step over the function, it hangs. Otherwise, if I step in and out, it doesn't.
Yes, the application is compiled with these options.

your output contains "WARNING: library configuration mismatch". Please retest with libs that match in their versions
Also full gdb output is needed, including registers and disassembly, if you can still reproduce it after fixing the libraries.
And if you say it hangs, try to find out not only one spot where execution happens but try to find out in which loop its trapped.

tested on a panda board, no crash. If you can still reproduce this with latest ffmpeg then we need much more information (full disassembly and register contents of where it crashes), valgrind output may or may not be usefull too. Even better would be if you could look at the code yourself and see if you spot why it hangs.
thanks